1 /************************************************************************* 2     > File Name: HeapSort.cpp 3     > Author: zhoukang 4     > Mail: zhoukang199191@126.com  5     > Created Time: 2014年08月11日 星期一 22时36分38秒 6  ************************************************************************/ 7  8 #include <iostream> 9 #include <vector>10 #include <algorithm>11 using namespace std;12 13 void max_heapfy(vector<int> & A,int index,int heapsize)14 {15     int l = 2*index+1;16     int r = 2*index+2;17 18     int largest = index;19     if(l <= heapsize && A[l] > A[index])20         largest = l;21     if(r <= heapsize && A[r] > A[largest])22         largest = r;23     if(largest != index)24     {25         swap(A[index],A[largest]);26         max_heapfy(A,largest,heapsize);27     }28 }29 30 void build_max_heap(vector<int> &A,int heapsize)31 {32 //    assert(heapsize >= 0);33     int i;34     for(i = heapsize/2-1 ; i >= 0 ; --i)35         max_heapfy(A,i,heapsize);36 }37 38 void heap_sort(vector<int> &A,int heapsize)39 {40     build_max_heap(A,heapsize);41     int i;42     for(i = heapsize-1; i > 0 ; --i )43     {44         swap(A[0],A[i]);45         max_heapfy(A,0,i);46     }47 }48 49 int main()50 {51     cout<<"before"<<endl;52     vector<int> A;53     A.push_back(3);54     A.push_back(1);55     A.push_back(2);56     heap_sort(A,3);57 }